256 BULLETIN: MUSEUM OF COMPARATIVE ZOOLOGY. 



Sterna dougalli gracilis (Gould). 



Two specimens, an adult $ and an adult 9 , taken June 7 on a small island 

 near Ishigaki. [Eggs were collected from June 19 to July 5.] These speci- 

 mens are extreme of the slender-billed small form to which Gould's name 

 gracilis applies. Specimens from western Europe and Africa agree closely in 

 measurements with those from eastern North America and the West Indies. 

 The red bill claimed as a character of gracilis may be due to age, many young 

 specimens from America having red bills, while in the adult birds it is black. 

 The differences between the two races of the Eoseate Tern in size and in measure- 

 ments of the bill are well marked. 



The Liu Kiu Islands specimens agree in measurements with the Australian 

 form, upon which Gould based his S. gracilis, and there can be no doubt of 

 their identity. 



The measurements of the two specimens are as follows : — 



No. Sex. W'ing. Tail.' Tarsus. Exposed Culmen. 



37.304 d" 221 110 20.2 36.6 



37.305 $ 216 109 19.4 36. 



Sterna fuliginosa crissalis (Baird). 



Two specimens from a small island near Iriomote, adult ^ and adult 9 > 

 taken June 10. [Eggs, one in a clutch, laid on the rock, were taken June 1.] 



Sterna bergii boreotis,- subsp. nov. 

 Type. — Mus- Conip. Zool., No. 37,301. 



A single adult $ in full breeding plumage from Ishigaki, June 15, 1899. 

 [Said to breed on Ishigaki.] 



Subspecijic Characters. — As small as the pale gray Sterna bergii poliocerca of 

 Tasmania and South Australia ; differing from it in having the wings, tail, and 

 mantle very dark smoke gray, almost mouse gray. 



Color. — Type, adult ^ in full plumage. Forehead, cheeks, lores, ear-coverts, 

 neck all round, and whole under parts, including lining of wing and bend of 

 wing, pure white ; crown and long occipital crest glossy black ; mantle, wings, 

 rump, upper tail coverts, and upper surface of middle rectrices dark smoke 

 gray, darkest on wings and middle of back, where the color is almost mouse 

 gray ; primary quills white; 1st primary with outer web, a band along quill 

 on inner web and tip blackish, with a silvery suffusion which is most marked 

 toward centre of feather; broad outer margin of inner web, below the black tip 



1 Tlie tails are measured to tlie end of tlie second rectrix, the streamer varying 

 too much in length individually to be taken into account. ,. 



'- Boreotis, northern. 



